One in 12 Brits wouldn’t spot a random £20 transaction on their bank statement, according to TotallyMoney .

The price comparison website carried out research using YouGov, and assumed each person holds one bank account and that there are 65 million active current accounts in the UK.

With one in 12 people admitting that a rogue £20 payment would go unnoticed, TotallyMoney calculated that the oversight could mean 5.4 million bank accounts could be at risk of fraud, potentially costing a total of £108m.

The study, carried out in partnership with Moneycomms, found one in seven people only check their bank account once a month or less.

Alastair Douglas, CEO of TotallyMoney, said: “For some people, a £20 transaction they don’t recognise isn’t the end of the world. But, it could be tell-tale of a bigger issue. In the past, we had to rely on monthly paper bank statements. Now, thanks to mobile apps, our bank accounts are at our fingertips, making it easier than ever to check our outgoings.

“Spotting and reporting anything you don’t recognise – no matter how small – could stop an incident of fraud in its tracks.”

Five tips to help bank customers stay alert to fraud

Go digital. A smartphone app or online banking makes it easier to check your statement regularly. You can often even set up alerts to get notified every time a transaction is made.

Hold on to receipts. Keep tabs of your contactless card transactions, by keeping the paper receipts until the money is taken out of your account.

Check your direct debits. Be aware of future direct debits and regular payments due before payday, so you know how much spending money you’ve got available.

Review your statements. Don’t ignore your monthly credit card and bank statements.

Check your credit report. Ensure you recognise everything on your credit report – especially credit searches.